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From an early discovery, pearls have been a form of mystical lure, prestige and elegance. As a treasured gemstone and jewelry adornment, dating back to Roman times, today, Pearls continue to make a statement as a classical mainstay, in jewelry and fashion.
Due to rarity and demand, the majority of Pearls today are cultured in their oceanic habitat by dedicated purveyors of the gem.
Organic by Nature
Cultured and Natural Pearls are made up of layers of nacre, a composition of Aragonite (a form of crystallized calcium carbonate) and conchiolin. Naturally, conchiolin serves as an adhesive for the aragonite platelets. These platelets, forming the beauty of nacreous layers give Pearls that satiny, lustrous appeal.
Among the species of two-shelled
mollusks, only very few are able to produce pearls. Both saltwater oysters and freshwater mussels have been cultured for several decades to produce cultured pearls. Saltwater oysters such as Pinctada maxima producing South Sea Pearls, P.margaritifera (Tahitian pearls) and P.fucata (Akoya pearls) are cultivated using bead nucleation.
As you can see in the picture to the left, magnification of a halve of a cultured Akoya pearl shows the bead nucleus made of shell and the nacreous layers that have developed around the bead nucleus.
The majority of cultured freshwater pearls are produced using tissue nucleation. Among the few mussels used for culturing are H.cumingi, M. nervosa and C.plicata.Tissue nucleation involves a piece of mantle tissue which is inserted into the mollusk and forms the nacreous layers producing a pearl.
Pearl Values
A combination of value factors is what determines a pearls worth. Similar to a descriptive system used for grading Diamonds, there are seven value factors used for grading and describing pearls.
Size
A pearl size varies among the pearl varieties. Although size does make a difference in price , a smaller pearl with other exceptional value factors can command as high of a price as a it’s larger counterpart.
Shape
Round, near round, Oval, Drop, Baroque and button. Generally rounds/spherical are the most valuable do to its rarity followed by symmetrical and baroque/ semi-baroque Pearls.
Color
Bodycolor is the primary,overall color of the pearl. The colors are influenced by the host species of the pearl such P.margaritifera, also known as the "black lip oyster", which produces the dark and cool bodycolors of Tahitian Pearls.
Pinctada maxima, has both golden and white lip oysters, which produce those beautiful, satiny, and warm colors of South Sea pearls.
Overtone
Overtone is a secondary, translucent color that appears over the bodycolor of the pearl, such as the rose overtone seen in this Akoya pearl to the left. Overtone can be present in various translucent colors adding a distinct overall beauty to the pearl.
Orient
Orient is the appearance of iridescent colors on the surface of the pearl, a rainbow effect shimmering across the pearls bodycolor. Orient is produced when light interacts with the nacrous layers of the pearl.
Luster
The quality of luster in a pearl is the amount of light return we see when looking at a pearl. This can range from excellent (bright and sharp), Good (bright but slightly hazy), fair (hazy) to poor (dull)
Surface Quality
Surface Quality is used to describe the natural surface characteristics such as small pits, bumps and spots seen in Pearls.Clean pearls can be spotless or have minute surface characteristics not easily observed. Lightly blemished have few characteristics, moderately blemished have noticeable characteristics and heavily blemished have obvious surface characteristics.
Matching
Pearl pairs in earrings, strands and pearl suites or sets usually affects the overall uniformity of the jewelry piece. However, mismatching can also have an artistic appeal as we see in multicolor strands or rings and earrings with a variation in color.
Pearl Treatments
In the pearl market today, the variation in color is abundant. From the bright eccentric colors of freshwater pearls available to the satiny neutral colors of South Sea Pearls, it gives customers an extensive choice to fancy their taste. Although not all pearls are enhanced, there are routine treatments (such as bleaching in Cultured Akoya Pearls) and color enhancing treatments (dyes and irradiation) in freshwater and saltwater pearls.
Some Dyes can be more easily observed, as shown in the picture to the left, of a bronze color enhanced freshwater pearl. Other methods, such as the use of silver nitrate to darken pearls is also used.Aside from sophisticated laboratory equipment, a close inspection of a pearl under the microscope is a good way to tell if there is dye or treatment. The picture below of the cultured pearl on the right is a good example of natural color, the green/violet hues are a good indicator in gray pearls.
Pearl Imitations
 
There are a variety of imitation pearls that are manufactured with the use of glass, plastics and other materials to resemble that of nacreous pearls. The pictures to the right show surface characteristics under magnification of natural nacre in a cultured Tahitian pearl showing step like, minute layers. The surface characteristics of an imitation glass pearl at a glance can be seemingly clean, but at closer inspection, the surface will be pitted, similar to the skin of an orange.
You can find Pearl Jewelry and Loose Pearls in our catalog under Pearl Jewelry and Gemstones.
We are welcome to any questions and inquiries regarding our products, and pearl information in general.
Please feel free to email us at info@pearladelmar.com.
Thanks for stopping by and visit us again soon, as we are constantly updating and adding products and information to our catalog.
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